This invention relates to endoscopic surgical instruments and more particularly to components thereof to facilitate assembly of surgical instruments in sturdy and releasable configuration for convenient and safe manipulation during surgical procedures.
Contemporary endoscopic surgical instruments commonly include an elongated shaft or cannula having multiple lumens extending therethrough from end to end for slidably positioning various surgical instruments therein to be manually manipulated from a proximal end of the cannula in order to affect various surgical procedures at the distal end. An endoscopic viewing instrument is usually included within one of such lumens, and bipolar scissors, or the like, may be disposed in another lumen through the elongated cannula to perform a surgical procedure within a field of view of the endoscope at the distal end of the cannula. The elongated cannula may be relatively rigid to provide adequate support for the endoscope over its entire length, and a surgical instrument such as bipolar scissors may exhibit some flexibility attributable to sufficiently small cross sectional area to slidably fit within a lumen of the elongated cannula. Such surgical instruments of sufficiently small cross sectional area to slide within a lumen of the cannula may undesirably flex and bend along a segment of its length not supported within the cannula as the cannula and the instruments assembled therein are manipulated relative to a surgical site on a patient, with concomitant breakage of the unsupported instruments.
In addition, a number of endoscopic instruments may be assembled within the narrow confines of the lumens within the cannula to fan out over a wider region near the proximal end in order to facilitate convenient mechanical attachment of video cameras, electrical and fluid connections, and the like. The proximal end of the cannula may be disposed within a supporting housing and the array of instruments and components within the cannula may be arranged to emanate from the housing at various locations and angles in order to avoid undesirable physical interference among instruments assembled about the proximal end of the cannula. An endoscope and associated video camera may be locked into position within the housing for proper rotational orientation relative to the cannula and housing, but may require quick disconnect mechanisms to facilitate rotational reorientation as desired during a surgical procedure. The distal end of the cannula commonly includes a tissue-dissecting tip for bluntly dissecting tissue within a visual field through the tip provided by the endoscope.
In accordance with one embodiment of the present invention, an instrument bridge is supported on a sturdy component assembled at the proximal end of a cannula to provide auxiliary support for less sturdy instruments that emanate from the proximal end at various angles and in spaced relationships about the proximal end of the cannula. In one embodiment of the present invention, a support member attaches to the cylindrical body of an endoscope and its associated video camera or detector at a location where the endoscope extends from the housing at the proximal end of the cannula. The support member protrudes laterally from the elongated axis of the endoscope to provide additional support for an endoscopic instrument of thin cross section, such as bipolar scissors. Specifically, the instrument bridge includes resilient clamps at opposite ends to resiliently grasp at the base end of the support the generally cylindrical barrel of an endoscope and to resiliently grasp at the lateral end of the support the generally cylindrical shape and narrow cross section of a surgical instrument. In this way, the surgical instrument of relatively narrow cross section and high flexibility is supported on and displaced away from the endoscope and endoscope attachments of relatively greater and more rigid cross section. In addition, the housing at the proximal end of the cannula may selectively lock and unlock the endoscope and associated video camera for selective rotational orientations within the housing. The base end of the support may also rotate about the barrel of the endoscope. The distal end of the cannula includes a transparent tip of blunt, eccentric conical shape to provide a relatively distortion-free field of view for the endoscope to facilitate blunt dissection of tissue, for example, along the course of a saphenous vein.